One vertex per element, one color per generator, with an edge from x to x·s.
(5,6)(7,11)(8,10)(9,12)(14,19)(16,25)(17,21)(20,26)(23,28)(24,27) involution — undirected(1,2)(3,4)(7,12)(9,11)(13,14,17,19,18,16,21,25)(15,20,24,26,22,23,27,28)(5,7,8,12)(6,9,10,11)(13,15,18,22)(14,20,16,23)(17,24,21,27)(19,26,25,28)(2,4)(6,10)(9,11)(15,22)(20,23)(24,27)(26,28) involution — undirected(13,16,17,25,18,14,21,19)(15,23,24,28,22,20,27,26)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.